RAW files conversion to Video

[multiweb (Marc)]

Originally Posted by troypiggo

I wouldn't vary aperture at all. Should just be able to jump the ISO up. Why are you restricting to 10s exposures? To stop star trailing when shooting on a tripod? If so, wouldn't have thought you need pinpoint stars in a video, you won't notice elongation after animation?

I'm trying to lock the exposure time to a maximum of 10s so I have the same interval for each new sub, this way I don't have to vary the frame rate for the video in the final. If the sub time increases to let's say 30s the video will accelerate for the longer subs because the sky moves 3x further 30s than 10s. I can compensate the signal by either opening the lens or modifying the ISO on the fly. Not sure how to set the camera to do this.

[multiweb (Marc)]

This time I got the transition in lighting alright but the video slows down.

[DavidTrap (David)]

Weird?????

Are you using an internal or external intervalometer? If it's internal, it may not be coping with the transition to long exposures.

I'd like to hear from the experts as to how they transition from day to night. Do they pick an arbitrary point in the evening (e.g. after astronomical twilight ends) when they shift to manual exposures of 20sec and maximum aperture, and the smooth out the transition using software?

DT

[multiweb (Marc)]

Originally Posted by DavidTrap

Weird?????

Are you using an internal or external intervalometer? If it's internal, it may not be coping with the transition to long exposures.

I'd like to hear from the experts as to how they transition from day to night. Do they pick an arbitrary point in the evening (e.g. after astronomical twilight ends) when they shift to manual exposures of 20sec and maximum aperture, and the smooth out the transition using software?

DT

I now have a HD version here where you can actually see some stars. I had the camera on auto with an external intervalometer and a delay of 10s. So it kept shooting short exposures within the delay segment of 10s. When it got dark I switched quickly to manual ISO 1600 and 10s exposures. Not sure why it slows down. Means the camera shot faster but it doesn't make sense because the gap is still 10s and the camera exposures were always contained within the 10s gap. I'm going to have to review the times on the raws and see what happened.

I had to key-in the brightness and contrast in the transition with software though (Premiere). You won't notice it as much in the sky but if you look at the illumination of the yellow bag on the top of the pier you'll see the break. You set 8 keys. Each for contrast and for brightness. 2 well before and after the transition so you can ease in and out and two at the frame level where the jump occurs. That's the second key you modify to try to match the previous frame which is a tad less saturated and much darker.

[DavidTrap (David)]

Hope you figure out why it got slower (cause I have no idea), and then we can all fallback on your experience when faced with the same conundrum!

Good luck,
DT

[multiweb (Marc)]

Originally Posted by DavidTrap

Hope you figure out why it got slower (cause I have no idea), and then we can all fallback on your experience when faced with the same conundrum!

Good luck,
DT

Well I think I got it now. My intervalometer was actually set to 20s so I stayed conservative with room to spare. All the shots just after sunset range between 1/30 to 5s. Then all of the sudden they double up in a very short period of time: 8s, 10s, 15s and even a few at 25s and 30s. So that's when I went over. The camera stayed on ISO 200 in automatic mode. When I switched to manual ISO 1600 then 10s subs were back to be shot every 10s, same as the beginning. If you look at the stars just when they start appearing within the clouds they're going slow. Then then accelerate (25 to 30s shots) then slow down to the same speed again. So it's working. I just have to avoid any subs bigger than let's say a 15s shot and I should be good to go. I'll test again tonight. Seems that the change in light is not linear. It starts slow then drops really fast.

[jjjnettie (Jeanette)]

I used to using Jasc Animation Shop. It was easy to use but I couldn't add music, and the compression was apt to be contrary resulting in some dud files. At the recommendation of Nick Howes, I downloaded Sony's "Vegas Movie Studio HD".
I tried it out once during the trial period and it was incredibly more sophisticated and pretty easy to learn. I bought the full version the other night.

[Bassnut (Fred)]

Originally Posted by DavidTrap

how they transition from day to night.

DT

Well, this is known in the timelapse trade as the "holy grail". Flicker free transition from day to night requires (apart from Bulb mode) the "lens twist" trick at small appatures (to prevent flicker) and exposure time, ISO and Apature change. This is all not possible right now automatically, the closest you can get is manually with a "Little Bramper" controller, or automatically (both without auto lens twist) with literally only the "Vandergraf Hart attack Machine", and you cant buy them, theres only 2 in existance . The Vandergraf Hart attack Machine will have auto lens twist in the future though, which hopefully then acheives the holy grail, Im working on it .

Originally Posted by multiweb

Well I think I got it now. My intervalometer was actually set to 20s so I stayed conservative with room to spare. All the shots just after sunset range between 1/30 to 5s. Then all of the sudden they double up in a very short period of time: 8s, 10s, 15s and even a few at 25s and 30s. So that's when I went over. The camera stayed on ISO 200 in automatic mode. When I switched to manual ISO 1600 then 10s subs were back to be shot every 10s, same as the beginning. If you look at the stars just when they start appearing within the clouds they're going slow. Then then accelerate (25 to 30s shots) then slow down to the same speed again. So it's working. I just have to avoid any subs bigger than let's say a 15s shot and I should be good to go. I'll test again tonight. Seems that the change in light is not linear. It starts slow then drops really fast.

Yes, make sure the interval is always longer than the longest auto exposure time. Light change at sunrise/sunset is fast and non linear. With a bit of practice, you should be able to make iso/ap changes at appropriate times to keep the exposures less than 10 secs and fix the histogram changes in post. If your using bulb mode (with an intervalvometer) though,you might like to use the "lens twist" trick whlist the lens is at f22-f8 if you can to avoid flicker, althought at fast exposures times, flash feedback is also handy but hard to impliment as you then need a way to time exposures from flash socket output after exposure actuation.

[multiweb (Marc)]

Originally Posted by jjjnettie

I used to using Jasc Animation Shop. It was easy to use but I couldn't add music, and the compression was apt to be contrary resulting in some dud files. At the recommendation of Nick Howes, I downloaded Sony's "Vegas Movie Studio HD".
I tried it out once during the trial period and it was incredibly more sophisticated and pretty easy to learn. I bought the full version the other night.

Sounds good JJJ. Will check it out too.

[multiweb (Marc)]

Originally Posted by Bassnut

Well, this is known in the timelapse trade as the "holy grail". Flicker free transition from day to night requires (apart from Bulb mode) the "lens twist" trick at small appatures (to prevent flicker) and exposure time, ISO and Apature change. This is all not possible right now automatically, the closest you can get is manually with a "Little Bramper" controller, or automatically (both without auto lens twist) with literally only the "Vandergraf Hart attack Machine", and you cant buy them, theres only 2 in existance . The Vandergraf Hart attack Machine will have auto lens twist in the future though, which hopefully then acheives the holy grail, Im working on it .

By lens twist you mean modifying the aperture? So would there be a setting to keep ISO constant and just modify the aperture of the lens in steps?

Originally Posted by Bassnut

Yes, make sure the interval is always longer than the longest auto exposure time. Light change at sunrise/sunset is fast and non linear. With a bit of practice, you should be able to make iso/ap changes at appropriate times to keep the exposures less than 10 secs and fix the histogram changes in post. If your using bulb mode (with an intervalvometer) though,you might like to use the "lens twist" trick whlist the lens is at f22-f8 if you can to avoid flicker, althought at fast exposures times, flash feedback is also handy but hard to impliment as you then need a way to time exposures from flash socket output after exposure actuation.

I use the intervalometer just to fire the shutter at set times. The camera takes care of ISO/Aperture/Exp time automatically. The problem I've been having is when it gets darker. Sub times increase very quickly and the only way to do a smooth transisiton would be to stay next to the camera making sure to bump the ISO manually so the exp time does run over. It seems automatic favours longer exposures rather than bumping ISO. I'd like to lock exp time and vary ISO.

[Bassnut (Fred)]

No, the lens twist is, at the required apature, say f22, push the depth of field button so the ap closes down, and at the same push the lens unlock button and at the same time twist the lens a few mm, say 5 untill the LCD display shows 00 apature. In auto you need to be in av mode so the exp time is auto. Select an ISO for reasonable exp times, iso doesn't Auto change. So the ap and iso are fixed and exp time changes. Manually change the iso as you go to keep exp times reasonable. At some stage when it gets darker and you've reached the max exp time you can have and the max Iso you can stand, twist the lens back on and switch to full auto or to tv mode ,to control max exp time, by setting the ISo to the highest you can stnd and manually change expoures times which will auto change ap. When the ap bottoms out, make sure the exp times are long enough for correct expoures untill you've reached the max exp time allowed (less than the period). Then you've hit a brick wall, min ap, max ISP and max exp time, after that let it go and the time lapse will just get darker if it's not already a full dark sky.

[multiweb (Marc)]

Thanks for the info. Will try that next time.

Originally Posted by Bassnut

No, the lens twist is, at the required apature, say f22, push the depth of field button so the ap closes down, and at the same push the lens unlock button and at the same time twist the lens a few mm, say 5 untill the LCD display shows 00 apature. In auto you need to be in av mode so the exp time is auto. Select an ISO for reasonable exp times, iso doesn't Auto change. So the ap and iso are fixed and exp time changes. Manually change the iso as you go to keep exp times reasonable. At some stage when it gets darker and you've reached the max exp time you can have and the max Iso you can stand, twist the lens back on and switch to full auto or to tv mode ,to control max exp time, by setting the ISo to the highest you can stnd and manually change expoures times which will auto change ap. When the ap bottoms out, make sure the exp times are long enough for correct expoures untill you've reached the max exp time allowed (less than the period). Then you've hit a brick wall, min ap, max ISP and max exp time, after that let it go and the time lapse will just get darker if it's not already a full dark sky.

[Bassnut (Fred)]

And........ Ive just down loaded Lightroom (Adobe, $124) and LRtimelapse (free). Its all freaking awesome for time lapse, have a look at the tutorials http://lrtimelapse.com/. It has tools for correcting the exposure jumps with manual cam changes and all kinds of other TL tools and it looks to be very comprehensive and easy to use. Going by the TL forums, its now by far the best way to produce jump/flicker free TL.

[troypiggo (Troy)]